Dog-strangling vine biocontrol agent Hypena opulenta is safe!

On October 1st, the Ottawa Citizen reported the
encouraging news that a biological control agent was released to combat pale
swallow-wort, also known as dog-strangling vine.Land owners were ecstatic to hear that after
years of trying in vain to rid their property of this scourge, there is now a
potential solution.Five-hundred
caterpillars of the moth Hypena opulenta,
originally from Ukraine, were placed out on September 20 to tell us whether the
moth is able to survive Canadian winter conditions.Some have voiced concern that the moth might attack other
plants. Local naturalist Dan Brunton,
quoted in the article, characterizes biological control as “ecological Russian
roulette”. On the contrary, I would like
to reassure the public that Hypena
opulenta has gone through a rigorous screening process that included a test
list of over 75 plant species, including an extensive selection of the closest
North American relatives of dog-strangling vine, the milkweeds. None of these plants were suitable for the
survival and development of Hypena
caterpillars. After nearly 10 years of research,
the petition to release Hypena in
Canada was approved by a panel of experts from throughout North America. Other potential agents were also considered,
but failed to pass the test of host specificity. The introduction of Hypena
opulenta does not pose a threat to native plants. The only threat to native plants is if we do
nothing--the dog-strangling vine itself has the documented ability to eliminate
populations of both common and rare plants. Its continued spread is degrading multiple
habitats across the province, including the globally rare alvars that are such
a treasure for Ontario.